5 Liferafts - Rigid and Inflatable

  5.16.2 The liferaft should be loaded with a mass equal to the mass of the number of persons for which it is to be approved and its equipment. With the liferaft in a free hanging position it should be pulled laterally to a position so that when released it will strike a rigid vertical surface at a velocity of 3.5 m/s. The liferaft should then be released to impact against the rigid vertical surface. After this test the liferaft should show no signs of damage which would affect its efficient functioning.

  5.16.3 The liferaft, loaded as prescribed in 5.16.2, should be suspended from an on-load release at a height of 3 m above the water, be released and allowed to fall freely into the water. The liferaft should then be examined to ensure that no damage has been sustained which would affect its efficient functioning.

  5.16.4 A davit-launched liferaft should, in addition to the boarding test prescribed in 5.8, be subjected to the following test. The liferaft, should be suspended from a liferaft launching appliance, or from a crane with a head sheave of similar height, and bowsed in to the ship's side or simulated ship's side. The liferaft should then be boarded by the number of persons for which it is to be approved of average mass 82.5 kg. There should be no undue distortion of the liferaft. The bowsing should then be released and the liferaft left hanging for 5 min. It should then be lowered to the sea or floor and unloaded. At least three tests are required in succession, with the hook of the lowering appliance so positioned that its distance from the ship's side is:

• .1 half the beam of the liferaft +150 mm;

• .2 half the beam of the liferaft; and

• .3 half the beam of the liferaft -150 mm.

The boarding, which is intended to simulate actual shipboard conditions, should be timed and the time recorded.

  5.17.1 It should be demonstrated that, in the event of any one of the buoyancy compartments being damaged or failing to inflate, the intact compartment or compartments should support, with positive freeboard over the liferaft's periphery, the number of persons for which the liferaft is to be approved. This can be demonstrated with persons each having a mass of 82.5 kg and seated in their normal positions or by an equally distributed mass.

  5.17.2 This test is not required for a canopied reversible liferaft. For this test the liferaft should be inverted so as to simulate inverted inflation.

• .1 the inflatable liferaft should be loaded with its heaviest equipment pack. All of the entrances, ports, and other openings in the liferaft canopy should be open in order to allow the infiltration of water into the canopy when capsized;

• .2 the canopy of the liferaft should then be completely filled with water. Except for an automatically self-righting liferaft, this may be accomplished, if necessary by partially collapsing the canopy support, or alternatively the uninflated liferaft should be flaked out onto the surface of the water upside down and inflation initiated. An automatically self-righting liferaft should self-right in this condition, and should become boardable in the upright position within 1 min after the start of the test. If the inflatable liferaft, other than an automatically self-righting liferaft, does not self-right, it should be allowed to remain in an inverted position for at least 10 min before righting is attempted;

• .3 the righting test should be carried out by the same team of persons required for the boarding test similarly clothed and wearing lifejackets and after completing the swim required in 5.8. At least one of the persons righting the inflatable liferaft should weigh less than 82.5 kg. Each person should attempt to right the liferaft unaided. The water should be of sufficient depth to give no external assistance to the swimmers when mounting the inverted liferaft;

• .4 the righting arrangements will be considered satisfactory if each person rights the liferaft unaided. There should be no damage to the structure of the inflatable liferaft, and the equipment pack should remain secured in its place.

  5.17.3 A liferaft, packed in each type of container, should be inflated by pulling the painter and the time recorded:

• .1 for it to become boardable, i.e. when buoyancy tubes are inflated to full shape and diameter;

• .2 for the cover to be erect; and

• .3 for the liferaft to reach its full operational pressure ^footnote when tested:

  • .3.1 at an ambient temperature of between 18°C and 20°C;

  • .3.2 at a temperature of -30°C; and

  • .3.3 at a temperature of +65°C.

  5.17.4 When inflated in an ambient temperature of between 18°C and 20°C, it should achieve total inflation in not more than 1 min. In the case of automatic self-righting liferaft, the liferaft should achieve total inflation and be boardable in the upright position in not more than 1 min, regardless of the orientation in which the liferaft inflates. The force required to pull the painter and start inflation should not exceed 150 N.

  5.17.5 For the inflation test at -30°C the packed liferaft should be kept at room temperature for at least 24 h, then placed in a refrigerated chamber at a temperature of -30°C for 24 h prior to inflation by pulling the painter. Under these conditions the liferaft should reach working pressure in 3 min. Two liferafts should be subject to an inflation test at this temperature. There should be no seam slippage, cracking, or other defect in the liferaft and it should be ready for use after the tests.

  5.17.6 For the inflation test at +65°C the packed liferaft should be kept at room temperature for at least 24 h, then placed in a heating chamber at a temperature of +65°C for not less than 7 h prior to inflation by pulling the painter. Under these conditions the gas pressure relief valves must be of sufficient capacity to prevent damage to the liferaft by excess pressure and to prevent the maximum pressure during the inflation from reaching twice the reseat pressure of the release valve. There must be no seam slippage, cracking or other defect in the liferaft.

  5.17.7 Each inflatable compartment in the liferaft should be tested to a pressure equal to three times the working pressure. Each pressure relief valve should be made inoperative, compressed air should be used to inflate the inflatable liferaft and the inflation source removed. The test should continue for at least 30 min. The pressure should not decrease by more than 5% as determined without compensating for temperature and atmospheric pressure changes, and there should be no seam slippage, cracking or other defect in the liferaft.

  5.17.8 The measurement of pressure drop due to leakage can be started when it has been assumed that compartment material has completed stretching due to the inflation pressure and achieved equilibrium.

  5.17.9

• .1 It should be demonstrated that sample seams, prepared in the same condition as in production, can withstand a test load equal to the minimum specified liferaft fabric tensile strength. Sewn seams on outer canopy fabric shall withstand a test load of at least 70% of the minimum specified fabric tensile strength when tested by the method described in ISO 1421:1998 and by using test samples as shown in figure 1 below.

• Samples of all types of sewing used in production shall be tested.

  Seam constructions in both warp and weft direction shall be tested.

  The test specimens should be cut out from pre-sewn samples of fabric and no locking of thread ends shall take place.

• .2 Weld strength

• .2.1 When tested by the method prescribed below, the load required to initiate failure of the weld should be not less than 175 N;

• .2.2 Specimens should be prepared and tested as given in .3.3 below:

• .3 Hydrolysis tests should be conducted on sample welded seams where thermoplastic coated materials are to be used. The tests should be conducted as follows:

• .3.1 When tested by the method prescribed below, the weld strength of the sample seam should achieve 125 N/25 mm minimum.

• .3.2 Test method:

  • .1 Store the test specimens for 12 weeks over water in a closed container at 93 ± 2°C.

  • .2 After the conditioning as above, dry the specimens for 1 h at 80 ± 2°C and condition at 20 ± 2°C, 65% RH for 24 h.

• .3.3 Welded test samples should be prepared as follows:

  Two samples of fabric 300 mm × 200 mm, cut with the short side parallel to the warp direction, should be superimposed face to back for double coated fabrics, or coated face to coated face for single or asymmetrically coated fabrics. They should be welded with a tool 10 ± 1 mm width of convenient length. 25 mm wide test specimens should be cut transversely to the line of the weld. The test samples should be mounted in a test machine as in ISO 1421:1998. The maximum peel load should be recorded.

Figure 1 Sample specification for sewn canopy seams

  5.17.10 It should be demonstrated by an overload test on the liferaft hanging from its centre support that the bridle system has an adequate factor of safety as follows:

• .1 the liferaft should be placed in a temperature of 20±3°C for a period of at least 6 h;

• .2 following this period of conditioning, the liferaft should be suspended from its lifting hook or bridle and the buoyancy chambers (not including an inflatable floor) inflated;

• .3 when fully inflated and when the relief valves have reseated themselves, all relief valves should be made inoperative;

• .4 the liferaft should then be lowered and loaded with a distributed mass equivalent to four times the mass of the number of persons for which it is to be approved and its equipment, the mass of each person being taken as 82.5 kg;

• .5 the liferaft should then be raised and remain suspended for at least 5 min;

• .6 the pressure before and after the test after the weight is removed and while it remains suspended, should be recorded; and

• .7 any dimensional deflections or distortions of the liferaft should be recorded. During the test and after its completion, the inflatable liferaft should remain suitable for its intended use.

  5.17.11 It should be demonstrated, after a period of 6 h in a chamber at a temperature of -30°C, that the liferaft will support a load of 1.1 times the number of persons for which it is to be approved and its equipment with all relief valves operative. The liferaft should be loaded with the test weight in the refrigerated chamber. The floor should not be inflated. The loaded inflatable liferaft should remain suspended for at least 5 min. If the inflatable liferaft must be removed from the chamber in order to suspend it, the inflatable liferaft should be suspended immediately upon removal from the chamber. During the test and after its completion, the inflatable liferaft should remain suitable for its intended use.

  5.17.12 The inflatable liferaft should be loaded with a weight equal to the mass of its heaviest equipment pack and the number of persons for which it is to be approved, the mass of each person being taken as 82.5 kg. Except for the floor which should not be inflated, the inflatable liferaft should be fully inflated with all relief valves operative. A liferaft should be lowered for a distance of at least 4.5 m in continuous contact against a structure erected to represent the side of a ship having a 20° adverse list. The height of the point from which the hook is suspended should be comparable to that of a shipboard launching appliance. During the test and after its completion, the liferaft should not sustain damage or distortion, or assume a position which would render it unsuitable for its intended purpose.

  5.17.13 The materials when tested should meet the following requirements:

• .1 The fabric should be marked in such a manner as to allow traceability of the fabric manufacturer and production lot number.

• .2 Tests and performance criteria

• .2.1 Test samples should be randomly selected, and test pieces cut from each sample as required by the relevant ISO standard or as otherwise prescribed for each individual test.

• .2.2 Fabric used for manufacture of buoyancy tubes, inflatable supports for canopies and floors should meet the following requirements:

• .2.2.1 Tensile strength

  When tested by the method described in ISO 1421:1998 the tensile strength should be a minimum of 2255 N/50 mm width for warp and weft. Maximum elongation, for the above should be 30% over a 200 mm gauge length, the elongation should be expressed as a percentage of the initial test length between the jaws. Where two layers of floor fabric are provided to form an inflatable floor the main floor should be as specified. The inner/outer layer may have a minimum tensile strength of 1470 N/50 mm widths in warp and weft direction.

• .2.2.2 Tear strength

  When tested with the apparatus described in ISO 1421:1998, the tear strength should be 1030 N minimum, in warp and weft directions. Where two layers of the floor fabric are provided to form an inflatable floor, the main floor should be as specified. The inner/outer layer may have a minimum tear strength of 735 N in warp and weft directions. The preparation of the test specimens should be as follows:

  • .1 from the test sample cut 3 specimens each in warp and weft directions, 76 ± 1 mm wide and 400 mm long, with the length closely parallel to the warp and weft yarns. Space the selection across the full length and width of the sample. Make a 12.5 mm cut across the middle of each specimen at right angles to the length.

  • .2 grip the specimen under test securely and evenly in the grips, which should be 200 mm apart, so that the specimen length is closely in the direction of the pull. Operate the machine in accordance with ISO 1421:1998. The maximum load sustained is recorded as the wound tear strength and the average for the 3 specimens is calculated.

• .2.2.3 Surface receptiveness and adhesion of surface coating

  • .1 When tested by the method described in ISO 2411:2000, the Surface Receptiveness on either face should not be less than 75 N/50 mm width.

  • .2 For dry Surface Coating Adhesion a minimum of 75 N/50 mm is required.

  • .3 For wet Surface Coating Adhesion as described in 2.2.3.8 a minimum of 50 N/50 mm is required.

  • .4 Each coated face should be tested. The specimens should be made up as in ISO 2411:2000 bonding like coated face to like coated face.

  • .5 The bonding used and the method of application should be agreed between the liferaft manufacturer and the finished fabric manufacturer, and should be the same as those used during the manufacture of the liferaft.

  • .6 On each test specimen the bonding between the adhesive or weld and the coating should be initially measured to determine the surface receptivity.

  • .7 The adhesion of the coating to the base textile is then measured by cutting through one coating layer to initiate the required mode of separation.

  • .8 After testing in .4 for adhesion of coating to the base textile the specimen should be immersed for 24 h in a 3% aqueous solution of sodium chloride at 20EC ± 2EC. At the end of the immersion period the specimen should be removed from the solution and while still wet tested by the method specified in ISO 2411:2000.

• .2.2.4 Effects of ageing

  • .1 Folding Test

    When tested as prescribed below, there should be no cracks, separation of plies or brittleness visible when the samples are inspected under a magnification of 2.

  • .2 Tensile Test

    When tested as prescribed below, the tensile strength after ageing should be not less than 90% of the original tensile strength before ageing.

  • .3.1 Ultra-Violet Resistance

    This test should be performed in accordance with the methods specified in ISO 4892-4:2004 - Open-flame carbon-arc lamps, as follows:

    • .1 Expose the conditioned samples to an enclosed carbon arc lamp without "Corex D" filters for 100 h. The carbons should be Copper Clad Sunshine Arc Type, No.22 for the upper pair and No.13 for the lower pair, or equivalent. Only the intended outside surface of the fabric is to be exposed to the arc in the testing apparatus. The specimens should be exposed to water spray, with the apparatus operated so that the specimens are exposed to successive cycles of 102 min of light without spray and 18 min of light with spray. The black panel temperature should be 80+5°C. The total exposure time should be 100 h.

    • .2 Test the tensile strength of the material after exposure following the procedure in .2.2.1. The tensile strength should be not less than 90% of the original tensile strength before ageing.

    • .3 The exposed material should be bent, more heavily coated side out, around a 3.2 mm mandrel and examined visually for cracking. There should be no cracking.

  • .3.2 Alternative Ultra-Violet Resistance

    Alternatively, this test may be performed in accordance with the methods specified in ISO 4892-2:2006 with amendment 1:2009 - Xenon Arc type testing. The specimens should be exposed under conditions specified below, using a controlled irradiance water cooled Xenon Arc apparatus for a total exposure time of 150 h.

  Exposure conditions	Dark Cycle (1 h)	Light cycle (2 h)
  Automatic irradiance (Filter Q/B)	Nil	0.55 W/m2 - at 340 nm
  Black panel temperature	38 ± 2°C	70 ± 2°C
  Dry bulb temperature	38 ± 2°C	47 ± 2°C
  Relative humidity	95 ± 5%	50 ± 5%
  Conditioning water	40 ± 4°C	45 ± 4°C
  Water spray	60 min on front and back of specimen	40 min - Nil	20 - min Front of specimen only	- 60 min Nil

  Only the intended outside surface of the fabric should be exposed to the arc. The tensile strength of the material should be tested after exposure following the procedure in 2.2.1. The tensile strength should be not less than 90% of the original strength before ageing. The exposed material should be bent, with heavily coated side out, around a 3.2 mm mandrel and each coated face examined visually for cracking. There should be no cracking during this examination.

  The performance requirements specified in this subparagraph relate to the behaviour of individual specimens under particular conditions of test. As the spectrum of light from the Carbon Arc differs from that of the Xenon Arc, caution should be exercised in interpreting the test results of both methods.

  • .4 Three separate specimens should be tested as follows:

    • .1 dimensional stability;

    • .2 folding; and

    • .3 tensile strength.

  For .1 and .2 cut from the test sample 4 specimens at least 100 mm square with the sides closely parallel to the warp and weft threads. Measure the dimensions of two specimens accurately for .1. For .3, cut two sets of specimens as in .2.2.1.

  • .5 When tested as prescribed below the difference in dimensions of the sample before and after ageing should not differ by more than 2%.

  • .6 Ageing of specimens test procedure:

    • .1 Freely suspend one specimen each for .2.2.4.4.1 and .2.2.4.4.2, and one set of specimens for 2.2.4.4.3 in air for seven days at 70E ± 2EC. Suspend the other specimens above water in a loosely closed vessel for seven days at 70E ± 2EC.

    • .2 Remove the two measured specimens from the ageing oven. After 15 min at room temperature measure the dimensions and report the percentage changes in warp and weft directions.

    • .3 Remove the other two specimens. After 15 min at room temperature, fold the specimens consecutively in two directions parallel to the edges at right angles to each other so as to reduce the exposed area of each specimen to one quarter of its original size. Unfold and refold along the same creases but with each fold reversed in direction. After each folding, press the fold by rubbing fingers and thumb along it: inspect the specimens for cracks, separation of plies, stickiness or brittleness.

    • .4 For the Tensile Strength Test remove the two sets of specimens from the ageing oven. Dry the wet aged specimens for 1 h in air at 70 ± 2°C, and then condition both sets for 24 h. Test in accordance with .2.2.1.

• .2.2.5 Low temperature flexing

  • .1 When tested at a temperature no higher then -50EC by the method prescribed below, there should be no visible cracking of the sample when inspected under a magnification of 2. The test should be independently applied to each face of the coated fabric.

  • .2 The apparatus, preparation of test specimens and test procedure should be as described in ISO 4675:1990, except that:

    • .1 when tested at the specified low temperature, no specimen should show cracks; and

    • .2 there should be 6 test specimens, 3 cut with the long side closely parallel to the warp and 3 cut with the long side closely parallel to the weft direction.

• .2.2.6 Flex cracking

  After the specimen has been conditioned by exposing the outer face to a 3% aqueous solution of sodium chloride for seven days at 20E ± 2EC, it should be tested as described in ISO 7854:1995. After 200,000 flexings, no cracking or delamination should be visible when inspected under a magnification of 2.

• .2.2.7 Porosity

  When tested by the method prescribed below and with a pressure of 27.5 kPa applied and maintained beneath the fabric, there should be no signs of any leakage over a minimum period of 5 min.

  • .1 Test for porosity

    A specimen of the fabric should be prepared and tested in accordance with ISO 15372:2000, paragraph 6.2.9.2.

• .2.2.8 Oil resistance

  • .1 When tested by the method prescribed below, after exposing the outer surface to oil IRM 901, for 2 h at 20± 2°C, there should be no separation of coating from textile and no residual tackiness when two exposed faces are pressed together. The coating should not smear when rubbed with a single pass of the finger.

  • .2 The test should be carried out not less than 16 h after vulcanization or curing.

  • .3 The apparatus, preparation of specimens and test procedure should be in accordance with ISO 15372:2000/Amd 1:2021, paragraph 6.2.5. Each coated face should be tested.

• .2.2.9 Weft distortion

  The weft distortion should be not more than the equivalent of 100 mm maximum over a fabric width of 1.5 m. A line should be drawn across the fabric at right angles to the selvedge. The weft distortion, skew and/or bow should be measured.

• .2.2.10 Resistance to blocking

  • .1 When tested by the method prescribed below, the fabric should exhibit no blocking.

  • .2 The preparation of specimens and test procedure should be in accordance with ISO 5978:1990 except that the duration of time under load should be 7 days.

• .2.2.11 Hydrolysis resistance for thermoplastic coated materials only

  • .1 When tested by the methods prescribed below, the following performance values should be achieved:

    .1	Coating adhesion	50 N/50mm minimum
    .2	Blocking resistance	100 g maximum
    .3	Folding test	No cracks, delamination or visual deterioration

  • .2 The following test requirements should apply to fabrics or test specimens which have been stored for 12 weeks over water in a closed container at 93EC.

  • .3 The following test should be performed after drying the specimens for 1 h at 80 ± 2°C, and conditioning at 20 ± 2°C, 65% RH for 24 h.

  • .4 The coating adhesion of the stored material specimen should be made up and tested in accordance with .2.2.3 after the requirements of .2.2.11.2 above have been carried out.

  • .5 The blocking resistance should be tested in accordance with .2.2.10.

  • .6 Two test samples 100 mm ± 2 mm square should be cut from the stored material. The samples should be folded as defined in .2.2.4.6.3 and examined for evidence of cracks, ply separation, stickiness or brittleness.

• .2.2.12 Ozone resistance

  • .1 When tested by the method prescribed below, no cracks should be visible at a magnification of 5.

  • .2 The preparation of samples and test procedure should be in accordance with specification ISO 3011:1997.

    The following conditions should apply:

    .1	Ozone concentration	50 pphm
    .2	Temperature	20 ± 2°C
    .3	Exposure time	8 h
    .4	Mandrel diameter	6 × sample thickness

  • .2.3 Fabric used for the manufacture of outer canopies should meet the following requirements:

• .2.3.1 Tensile strength

  When tested by the method prescribed in .2.2.1, the tensile strength should be minimum 930N/50 mm of width in warp and weft directions.

• .2.3.2 Tear strength

  When tested by the method prescribed in .2.2.2, the tear strength should be minimum 490 N in warp and weft directions.

• .2.3.3 Low temperature flexing

  When tested at a temperature not higher than -30EC by the method prescribed in .2.2.5, there should be no visible cracking of the sample when inspected under a magnification of 2.

  The test should be independently applied to each face of the coated fabric.

• .2.3.4 Waterproofness

  • .1 When tested by the method prescribed below, no water should pass through the cone within 30 min. The coated fabric should not contain any material that is known to be injurious to a survivor drinking rainwater collected from the canopy.

    Fabrics may be coated on one or both sides.

  • .2 The test specimen should be cut to a size of 300 mm × times; times; times; 300 mm and tested in accordance with the following procedure:

    Fold the specimen twice at right angles and open it out into the form of a cone. Secure the cone with a paper clip and insert it into a suitable funnel supported on a flask. Pour 500 ml of water into the cone. Record any penetration of water to the outside of the cone after 30 min.

• .2.3.5 Surface receptiveness and adhesion of surface coating

  When tested by the method prescribed in .2.2.3, the surface receptiveness on either face should not be less than 25 N/50 mm width surface.

  For coating adhesion a minimum of 25 N/50 mm is required.

• .2.3.6 Colour

  The liferaft canopy should be evaluated after the mooring out test in 5.5 or an equivalent method using artificial light to determine whether the coating is sufficiently colour fast.

• .2.3.7 Effects of ageing

  • .1 Folding Test.

    When tested by the method prescribed in .2.2.4, there should be no cracks, separation of plies or brittleness visible when the samples are inspected under a magnification of 2.

  • .2 Tensile Test.

    When tested by the method prescribed in .2.2.4, at least 90% of the original tensile strength should be retained in both warp and weft directions.

• .2.4 Fabric used for the manufacture of inner canopies should meet the following requirements:

• .2.4.1 Tensile strength

  When tested by the method prescribed in .2.2.1, the tensile strength should be minimum 100 N/50 mm of width in warp and weft directions.

• .2.4.2 Porosity

  As the inner canopy serves as a barrier to provide a static layer of air, it should either be of a close weave construction or have a low porosity to air.